What is 3D printing?

3D printing is a type of manufacturing that allows three-dimensional objects to be created using a computer, software and a 3D printer.The technology is decades-old, but 3D printers have become much cheaper since 2010, with some home kits now selling for under $500.

Home enthusiasts can make their own designs of 3D objects using specialist software, or download instructions from online repositories providing thousands of open-source designs.

Also known as additive fabrication, the process involves creating the object layer by layer, using a variety of materials, such as plastic, glass, metal and ceramic.

There are several ways these materials can be turned into the desired shape.

For example:

Molten polymers are extruded into shape and then solidify as they cool

A fluid can be jet-inked onto a surface, and then turned into a solid structure through a chemical reaction

Metal objects can be built by laying metal in powder form, then welding selected areas with a laser

Living cells can be printed with a bio-ink formulation, to build tissue and organs layer by layer

3D printers are already being used to produce toys, car parts, prosthetic limbs, and even 'self-replicating' 3D printers themselves.

Biotechnology firms are beginning to use 3D printing to print animal cells and reproduce nerves, muscles and bones.

Meanwhile, firearm enthusiasts are working on downloadable gun designs, and construction entrepreneurs hope to use 3D printing to build entire houses.

The process often reduces the amount of waste that is produced compared to other manufacturing techniques, like milling metal on a lathe.

Some of the drawbacks include the slow speed of fabrication and limits on the kinds of materials that can be used.